config.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  * Copyright (C) Johannes Schindelin, 2005
   6  *
   7  */
   8 #include "cache.h"
   9 #include "exec_cmd.h"
  10
  11 #define MAXNAME (256)
  12
  13 static FILE *config_file;
  14 static const char *config_file_name;
  15 static int config_linenr;
  16 static int config_file_eof;
  17 static int zlib_compression_seen;
  18
  19 const char *config_exclusive_filename = NULL;
  20
  21 static int get_next_char(void)
  22 {
  23         int c;
  24         FILE *f;
  25
  26         c = '\n';
  27         if ((f = config_file) != NULL) {
  28                 c = fgetc(f);
  29                 if (c == '\r') {
  30                         /* DOS like systems */
  31                         c = fgetc(f);
  32                         if (c != '\n') {
  33                                 ungetc(c, f);
  34                                 c = '\r';
  35                         }
  36                 }
  37                 if (c == '\n')
  38                         config_linenr++;
  39                 if (c == EOF) {
  40                         config_file_eof = 1;
  41                         c = '\n';
  42                 }
  43         }
  44         return c;
  45 }
  46
  47 static char *parse_value(void)
  48 {
  49         static char value[1024];
  50         int quote = 0, comment = 0, len = 0, space = 0;
  51
  52         for (;;) {
  53                 int c = get_next_char();
  54                 if (len >= sizeof(value))
  55                         return NULL;
  56                 if (c == '\n') {
  57                         if (quote)
  58                                 return NULL;
  59                         value[len] = 0;
  60                         return value;
  61                 }
  62                 if (comment)
  63                         continue;
  64                 if (isspace(c) && !quote) {
  65                         space = 1;
  66                         continue;
  67                 }
  68                 if (!quote) {
  69                         if (c == ';' || c == '#') {
  70                                 comment = 1;
  71                                 continue;
  72                         }
  73                 }
  74                 if (space) {
  75                         if (len)
  76                                 value[len++] = ' ';
  77                         space = 0;
  78                 }
  79                 if (c == '\\') {
  80                         c = get_next_char();
  81                         switch (c) {
  82                         case '\n':
  83                                 continue;
  84                         case 't':
  85                                 c = '\t';
  86                                 break;
  87                         case 'b':
  88                                 c = '\b';
  89                                 break;
  90                         case 'n':
  91                                 c = '\n';
  92                                 break;
  93                         /* Some characters escape as themselves */
  94                         case '\\': case '"':
  95                                 break;
  96                         /* Reject unknown escape sequences */
  97                         default:
  98                                 return NULL;
  99                         }
 100                         value[len++] = c;
 101                         continue;
 102                 }
 103                 if (c == '"') {
 104                         quote = 1-quote;
 105                         continue;
 106                 }
 107                 value[len++] = c;
 108         }
 109 }
 110
 111 static inline int iskeychar(int c)
 112 {
 113         return isalnum(c) || c == '-';
 114 }
 115
 116 static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
 117 {
 118         int c;
 119         char *value;
 120
 121         /* Get the full name */
 122         for (;;) {
 123                 c = get_next_char();
 124                 if (config_file_eof)
 125                         break;
 126                 if (!iskeychar(c))
 127                         break;
 128                 name[len++] = tolower(c);
 129                 if (len >= MAXNAME)
 130                         return -1;
 131         }
 132         name[len] = 0;
 133         while (c == ' ' || c == '\t')
 134                 c = get_next_char();
 135
 136         value = NULL;
 137         if (c != '\n') {
 138                 if (c != '=')
 139                         return -1;
 140                 value = parse_value();
 141                 if (!value)
 142                         return -1;
 143         }
 144         return fn(name, value, data);
 145 }
 146
 147 static int get_extended_base_var(char *name, int baselen, int c)
 148 {
 149         do {
 150                 if (c == '\n')
 151                         return -1;
 152                 c = get_next_char();
 153         } while (isspace(c));
 154
 155         /* We require the format to be '[base "extension"]' */
 156         if (c != '"')
 157                 return -1;
 158         name[baselen++] = '.';
 159
 160         for (;;) {
 161                 int c = get_next_char();
 162                 if (c == '\n')
 163                         return -1;
 164                 if (c == '"')
 165                         break;
 166                 if (c == '\\') {
 167                         c = get_next_char();
 168                         if (c == '\n')
 169                                 return -1;
 170                 }
 171                 name[baselen++] = c;
 172                 if (baselen > MAXNAME / 2)
 173                         return -1;
 174         }
 175
 176         /* Final ']' */
 177         if (get_next_char() != ']')
 178                 return -1;
 179         return baselen;
 180 }
 181
 182 static int get_base_var(char *name)
 183 {
 184         int baselen = 0;
 185
 186         for (;;) {
 187                 int c = get_next_char();
 188                 if (config_file_eof)
 189                         return -1;
 190                 if (c == ']')
 191                         return baselen;
 192                 if (isspace(c))
 193                         return get_extended_base_var(name, baselen, c);
 194                 if (!iskeychar(c) && c != '.')
 195                         return -1;
 196                 if (baselen > MAXNAME / 2)
 197                         return -1;
 198                 name[baselen++] = tolower(c);
 199         }
 200 }
 201
 202 static int git_parse_file(config_fn_t fn, void *data)
 203 {
 204         int comment = 0;
 205         int baselen = 0;
 206         static char var[MAXNAME];
 207
 208         /* U+FEFF Byte Order Mark in UTF8 */
 209         static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
 210         const unsigned char *bomptr = utf8_bom;
 211
 212         for (;;) {
 213                 int c = get_next_char();
 214                 if (bomptr && *bomptr) {
 215                         /* We are at the file beginning; skip UTF8-encoded BOM
 216                          * if present. Sane editors won't put this in on their
 217                          * own, but e.g. Windows Notepad will do it happily. */
 218                         if ((unsigned char) c == *bomptr) {
 219                                 bomptr++;
 220                                 continue;
 221                         } else {
 222                                 /* Do not tolerate partial BOM. */
 223                                 if (bomptr != utf8_bom)
 224                                         break;
 225                                 /* No BOM at file beginning. Cool. */
 226                                 bomptr = NULL;
 227                         }
 228                 }
 229                 if (c == '\n') {
 230                         if (config_file_eof)
 231                                 return 0;
 232                         comment = 0;
 233                         continue;
 234                 }
 235                 if (comment || isspace(c))
 236                         continue;
 237                 if (c == '#' || c == ';') {
 238                         comment = 1;
 239                         continue;
 240                 }
 241                 if (c == '[') {
 242                         baselen = get_base_var(var);
 243                         if (baselen <= 0)
 244                                 break;
 245                         var[baselen++] = '.';
 246                         var[baselen] = 0;
 247                         continue;
 248                 }
 249                 if (!isalpha(c))
 250                         break;
 251                 var[baselen] = tolower(c);
 252                 if (get_value(fn, data, var, baselen+1) < 0)
 253                         break;
 254         }
 255         die("bad config file line %d in %s", config_linenr, config_file_name);
 256 }
 257
 258 static int parse_unit_factor(const char *end, unsigned long *val)
 259 {
 260         if (!*end)
 261                 return 1;
 262         else if (!strcasecmp(end, "k")) {
 263                 *val *= 1024;
 264                 return 1;
 265         }
 266         else if (!strcasecmp(end, "m")) {
 267                 *val *= 1024 * 1024;
 268                 return 1;
 269         }
 270         else if (!strcasecmp(end, "g")) {
 271                 *val *= 1024 * 1024 * 1024;
 272                 return 1;
 273         }
 274         return 0;
 275 }
 276
 277 static int git_parse_long(const char *value, long *ret)
 278 {
 279         if (value && *value) {
 280                 char *end;
 281                 long val = strtol(value, &end, 0);
 282                 unsigned long factor = 1;
 283                 if (!parse_unit_factor(end, &factor))
 284                         return 0;
 285                 *ret = val * factor;
 286                 return 1;
 287         }
 288         return 0;
 289 }
 290
 291 int git_parse_ulong(const char *value, unsigned long *ret)
 292 {
 293         if (value && *value) {
 294                 char *end;
 295                 unsigned long val = strtoul(value, &end, 0);
 296                 if (!parse_unit_factor(end, &val))
 297                         return 0;
 298                 *ret = val;
 299                 return 1;
 300         }
 301         return 0;
 302 }
 303
 304 static void die_bad_config(const char *name)
 305 {
 306         if (config_file_name)
 307                 die("bad config value for '%s' in %s", name, config_file_name);
 308         die("bad config value for '%s'", name);
 309 }
 310
 311 int git_config_int(const char *name, const char *value)
 312 {
 313         long ret = 0;
 314         if (!git_parse_long(value, &ret))
 315                 die_bad_config(name);
 316         return ret;
 317 }
 318
 319 unsigned long git_config_ulong(const char *name, const char *value)
 320 {
 321         unsigned long ret;
 322         if (!git_parse_ulong(value, &ret))
 323                 die_bad_config(name);
 324         return ret;
 325 }
 326
 327 int git_config_bool_or_int(const char *name, const char *value, int *is_bool)
 328 {
 329         *is_bool = 1;
 330         if (!value)
 331                 return 1;
 332         if (!*value)
 333                 return 0;
 334         if (!strcasecmp(value, "true") || !strcasecmp(value, "yes"))
 335                 return 1;
 336         if (!strcasecmp(value, "false") || !strcasecmp(value, "no"))
 337                 return 0;
 338         *is_bool = 0;
 339         return git_config_int(name, value);
 340 }
 341
 342 int git_config_bool(const char *name, const char *value)
 343 {
 344         int discard;
 345         return !!git_config_bool_or_int(name, value, &discard);
 346 }
 347
 348 int git_config_string(const char **dest, const char *var, const char *value)
 349 {
 350         if (!value)
 351                 return config_error_nonbool(var);
 352         *dest = xstrdup(value);
 353         return 0;
 354 }
 355
 356 static int git_default_core_config(const char *var, const char *value)
 357 {
 358         /* This needs a better name */
 359         if (!strcmp(var, "core.filemode")) {
 360                 trust_executable_bit = git_config_bool(var, value);
 361                 return 0;
 362         }
 363         if (!strcmp(var, "core.trustctime")) {
 364                 trust_ctime = git_config_bool(var, value);
 365                 return 0;
 366         }
 367
 368         if (!strcmp(var, "core.quotepath")) {
 369                 quote_path_fully = git_config_bool(var, value);
 370                 return 0;
 371         }
 372
 373         if (!strcmp(var, "core.symlinks")) {
 374                 has_symlinks = git_config_bool(var, value);
 375                 return 0;
 376         }
 377
 378         if (!strcmp(var, "core.ignorecase")) {
 379                 ignore_case = git_config_bool(var, value);
 380                 return 0;
 381         }
 382
 383         if (!strcmp(var, "core.bare")) {
 384                 is_bare_repository_cfg = git_config_bool(var, value);
 385                 return 0;
 386         }
 387
 388         if (!strcmp(var, "core.ignorestat")) {
 389                 assume_unchanged = git_config_bool(var, value);
 390                 return 0;
 391         }
 392
 393         if (!strcmp(var, "core.prefersymlinkrefs")) {
 394                 prefer_symlink_refs = git_config_bool(var, value);
 395                 return 0;
 396         }
 397
 398         if (!strcmp(var, "core.logallrefupdates")) {
 399                 log_all_ref_updates = git_config_bool(var, value);
 400                 return 0;
 401         }
 402
 403         if (!strcmp(var, "core.warnambiguousrefs")) {
 404                 warn_ambiguous_refs = git_config_bool(var, value);
 405                 return 0;
 406         }
 407
 408         if (!strcmp(var, "core.loosecompression")) {
 409                 int level = git_config_int(var, value);
 410                 if (level == -1)
 411                         level = Z_DEFAULT_COMPRESSION;
 412                 else if (level < 0 || level > Z_BEST_COMPRESSION)
 413                         die("bad zlib compression level %d", level);
 414                 zlib_compression_level = level;
 415                 zlib_compression_seen = 1;
 416                 return 0;
 417         }
 418
 419         if (!strcmp(var, "core.compression")) {
 420                 int level = git_config_int(var, value);
 421                 if (level == -1)
 422                         level = Z_DEFAULT_COMPRESSION;
 423                 else if (level < 0 || level > Z_BEST_COMPRESSION)
 424                         die("bad zlib compression level %d", level);
 425                 core_compression_level = level;
 426                 core_compression_seen = 1;
 427                 if (!zlib_compression_seen)
 428                         zlib_compression_level = level;
 429                 return 0;
 430         }
 431
 432         if (!strcmp(var, "core.packedgitwindowsize")) {
 433                 int pgsz_x2 = getpagesize() * 2;
 434                 packed_git_window_size = git_config_int(var, value);
 435
 436                 /* This value must be multiple of (pagesize * 2) */
 437                 packed_git_window_size /= pgsz_x2;
 438                 if (packed_git_window_size < 1)
 439                         packed_git_window_size = 1;
 440                 packed_git_window_size *= pgsz_x2;
 441                 return 0;
 442         }
 443
 444         if (!strcmp(var, "core.packedgitlimit")) {
 445                 packed_git_limit = git_config_int(var, value);
 446                 return 0;
 447         }
 448
 449         if (!strcmp(var, "core.deltabasecachelimit")) {
 450                 delta_base_cache_limit = git_config_int(var, value);
 451                 return 0;
 452         }
 453
 454         if (!strcmp(var, "core.autocrlf")) {
 455                 if (value && !strcasecmp(value, "input")) {
 456                         auto_crlf = -1;
 457                         return 0;
 458                 }
 459                 auto_crlf = git_config_bool(var, value);
 460                 return 0;
 461         }
 462
 463         if (!strcmp(var, "core.safecrlf")) {
 464                 if (value && !strcasecmp(value, "warn")) {
 465                         safe_crlf = SAFE_CRLF_WARN;
 466                         return 0;
 467                 }
 468                 safe_crlf = git_config_bool(var, value);
 469                 return 0;
 470         }
 471
 472         if (!strcmp(var, "core.notesref")) {
 473                 notes_ref_name = xstrdup(value);
 474                 return 0;
 475         }
 476
 477         if (!strcmp(var, "core.pager"))
 478                 return git_config_string(&pager_program, var, value);
 479
 480         if (!strcmp(var, "core.editor"))
 481                 return git_config_string(&editor_program, var, value);
 482
 483         if (!strcmp(var, "core.excludesfile"))
 484                 return git_config_string(&excludes_file, var, value);
 485
 486         if (!strcmp(var, "core.whitespace")) {
 487                 if (!value)
 488                         return config_error_nonbool(var);
 489                 whitespace_rule_cfg = parse_whitespace_rule(value);
 490                 return 0;
 491         }
 492
 493         if (!strcmp(var, "core.fsyncobjectfiles")) {
 494                 fsync_object_files = git_config_bool(var, value);
 495                 return 0;
 496         }
 497
 498         if (!strcmp(var, "core.preloadindex")) {
 499                 core_preload_index = git_config_bool(var, value);
 500                 return 0;
 501         }
 502
 503         /* Add other config variables here and to Documentation/config.txt. */
 504         return 0;
 505 }
 506
 507 static int git_default_user_config(const char *var, const char *value)
 508 {
 509         if (!strcmp(var, "user.name")) {
 510                 if (!value)
 511                         return config_error_nonbool(var);
 512                 strlcpy(git_default_name, value, sizeof(git_default_name));
 513                 if (git_default_email[0])
 514                         user_ident_explicitly_given = 1;
 515                 return 0;
 516         }
 517
 518         if (!strcmp(var, "user.email")) {
 519                 if (!value)
 520                         return config_error_nonbool(var);
 521                 strlcpy(git_default_email, value, sizeof(git_default_email));
 522                 if (git_default_name[0])
 523                         user_ident_explicitly_given = 1;
 524                 return 0;
 525         }
 526
 527         /* Add other config variables here and to Documentation/config.txt. */
 528         return 0;
 529 }
 530
 531 static int git_default_i18n_config(const char *var, const char *value)
 532 {
 533         if (!strcmp(var, "i18n.commitencoding"))
 534                 return git_config_string(&git_commit_encoding, var, value);
 535
 536         if (!strcmp(var, "i18n.logoutputencoding"))
 537                 return git_config_string(&git_log_output_encoding, var, value);
 538
 539         /* Add other config variables here and to Documentation/config.txt. */
 540         return 0;
 541 }
 542
 543 static int git_default_branch_config(const char *var, const char *value)
 544 {
 545         if (!strcmp(var, "branch.autosetupmerge")) {
 546                 if (value && !strcasecmp(value, "always")) {
 547                         git_branch_track = BRANCH_TRACK_ALWAYS;
 548                         return 0;
 549                 }
 550                 git_branch_track = git_config_bool(var, value);
 551                 return 0;
 552         }
 553         if (!strcmp(var, "branch.autosetuprebase")) {
 554                 if (!value)
 555                         return config_error_nonbool(var);
 556                 else if (!strcmp(value, "never"))
 557                         autorebase = AUTOREBASE_NEVER;
 558                 else if (!strcmp(value, "local"))
 559                         autorebase = AUTOREBASE_LOCAL;
 560                 else if (!strcmp(value, "remote"))
 561                         autorebase = AUTOREBASE_REMOTE;
 562                 else if (!strcmp(value, "always"))
 563                         autorebase = AUTOREBASE_ALWAYS;
 564                 else
 565                         return error("Malformed value for %s", var);
 566                 return 0;
 567         }
 568
 569         /* Add other config variables here and to Documentation/config.txt. */
 570         return 0;
 571 }
 572
 573 int git_default_config(const char *var, const char *value, void *dummy)
 574 {
 575         if (!prefixcmp(var, "core."))
 576                 return git_default_core_config(var, value);
 577
 578         if (!prefixcmp(var, "user."))
 579                 return git_default_user_config(var, value);
 580
 581         if (!prefixcmp(var, "i18n."))
 582                 return git_default_i18n_config(var, value);
 583
 584         if (!prefixcmp(var, "branch."))
 585                 return git_default_branch_config(var, value);
 586
 587         if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 588                 pager_use_color = git_config_bool(var,value);
 589                 return 0;
 590         }
 591
 592         /* Add other config variables here and to Documentation/config.txt. */
 593         return 0;
 594 }
 595
 596 int git_config_from_file(config_fn_t fn, const char *filename, void *data)
 597 {
 598         int ret;
 599         FILE *f = fopen(filename, "r");
 600
 601         ret = -1;
 602         if (f) {
 603                 config_file = f;
 604                 config_file_name = filename;
 605                 config_linenr = 1;
 606                 config_file_eof = 0;
 607                 ret = git_parse_file(fn, data);
 608                 fclose(f);
 609                 config_file_name = NULL;
 610         }
 611         return ret;
 612 }
 613
 614 const char *git_etc_gitconfig(void)
 615 {
 616         static const char *system_wide;
 617         if (!system_wide)
 618                 system_wide = system_path(ETC_GITCONFIG);
 619         return system_wide;
 620 }
 621
 622 static int git_env_bool(const char *k, int def)
 623 {
 624         const char *v = getenv(k);
 625         return v ? git_config_bool(k, v) : def;
 626 }
 627
 628 int git_config_system(void)
 629 {
 630         return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
 631 }
 632
 633 int git_config_global(void)
 634 {
 635         return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
 636 }
 637
 638 int git_config(config_fn_t fn, void *data)
 639 {
 640         int ret = 0;
 641         char *repo_config = NULL;
 642         const char *home = NULL;
 643
 644         /* Setting $GIT_CONFIG makes git read _only_ the given config file. */
 645         if (config_exclusive_filename)
 646                 return git_config_from_file(fn, config_exclusive_filename, data);
 647         if (git_config_system() && !access(git_etc_gitconfig(), R_OK))
 648                 ret += git_config_from_file(fn, git_etc_gitconfig(),
 649                                             data);
 650
 651         home = getenv("HOME");
 652         if (git_config_global() && home) {
 653                 char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 654                 if (!access(user_config, R_OK))
 655                         ret += git_config_from_file(fn, user_config, data);
 656                 free(user_config);
 657         }
 658
 659         repo_config = git_pathdup("config");
 660         ret += git_config_from_file(fn, repo_config, data);
 661         free(repo_config);
 662         return ret;
 663 }
 664
 665 /*
 666  * Find all the stuff for git_config_set() below.
 667  */
 668
 669 #define MAX_MATCHES 512
 670
 671 static struct {
 672         int baselen;
 673         char* key;
 674         int do_not_match;
 675         regex_t* value_regex;
 676         int multi_replace;
 677         size_t offset[MAX_MATCHES];
 678         enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 679         int seen;
 680 } store;
 681
 682 static int matches(const char* key, const char* value)
 683 {
 684         return !strcmp(key, store.key) &&
 685                 (store.value_regex == NULL ||
 686                  (store.do_not_match ^
 687                   !regexec(store.value_regex, value, 0, NULL, 0)));
 688 }
 689
 690 static int store_aux(const char* key, const char* value, void *cb)
 691 {
 692         const char *ep;
 693         size_t section_len;
 694
 695         switch (store.state) {
 696         case KEY_SEEN:
 697                 if (matches(key, value)) {
 698                         if (store.seen == 1 && store.multi_replace == 0) {
 699                                 warning("%s has multiple values", key);
 700                         } else if (store.seen >= MAX_MATCHES) {
 701                                 error("too many matches for %s", key);
 702                                 return 1;
 703                         }
 704
 705                         store.offset[store.seen] = ftell(config_file);
 706                         store.seen++;
 707                 }
 708                 break;
 709         case SECTION_SEEN:
 710                 /*
 711                  * What we are looking for is in store.key (both
 712                  * section and var), and its section part is baselen
 713                  * long.  We found key (again, both section and var).
 714                  * We would want to know if this key is in the same
 715                  * section as what we are looking for.  We already
 716                  * know we are in the same section as what should
 717                  * hold store.key.
 718                  */
 719                 ep = strrchr(key, '.');
 720                 section_len = ep - key;
 721
 722                 if ((section_len != store.baselen) ||
 723                     memcmp(key, store.key, section_len+1)) {
 724                         store.state = SECTION_END_SEEN;
 725                         break;
 726                 }
 727
 728                 /*
 729                  * Do not increment matches: this is no match, but we
 730                  * just made sure we are in the desired section.
 731                  */
 732                 store.offset[store.seen] = ftell(config_file);
 733                 /* fallthru */
 734         case SECTION_END_SEEN:
 735         case START:
 736                 if (matches(key, value)) {
 737                         store.offset[store.seen] = ftell(config_file);
 738                         store.state = KEY_SEEN;
 739                         store.seen++;
 740                 } else {
 741                         if (strrchr(key, '.') - key == store.baselen &&
 742                               !strncmp(key, store.key, store.baselen)) {
 743                                         store.state = SECTION_SEEN;
 744                                         store.offset[store.seen] = ftell(config_file);
 745                         }
 746                 }
 747         }
 748         return 0;
 749 }
 750
 751 static int write_error(const char *filename)
 752 {
 753         error("failed to write new configuration file %s", filename);
 754
 755         /* Same error code as "failed to rename". */
 756         return 4;
 757 }
 758
 759 static int store_write_section(int fd, const char* key)
 760 {
 761         const char *dot;
 762         int i, success;
 763         struct strbuf sb = STRBUF_INIT;
 764
 765         dot = memchr(key, '.', store.baselen);
 766         if (dot) {
 767                 strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
 768                 for (i = dot - key + 1; i < store.baselen; i++) {
 769                         if (key[i] == '"' || key[i] == '\\')
 770                                 strbuf_addch(&sb, '\\');
 771                         strbuf_addch(&sb, key[i]);
 772                 }
 773                 strbuf_addstr(&sb, "\"]\n");
 774         } else {
 775                 strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
 776         }
 777
 778         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 779         strbuf_release(&sb);
 780
 781         return success;
 782 }
 783
 784 static int store_write_pair(int fd, const char* key, const char* value)
 785 {
 786         int i, success;
 787         int length = strlen(key + store.baselen + 1);
 788         const char *quote = "";
 789         struct strbuf sb = STRBUF_INIT;
 790
 791         /*
 792          * Check to see if the value needs to be surrounded with a dq pair.
 793          * Note that problematic characters are always backslash-quoted; this
 794          * check is about not losing leading or trailing SP and strings that
 795          * follow beginning-of-comment characters (i.e. ';' and '#') by the
 796          * configuration parser.
 797          */
 798         if (value[0] == ' ')
 799                 quote = "\"";
 800         for (i = 0; value[i]; i++)
 801                 if (value[i] == ';' || value[i] == '#')
 802                         quote = "\"";
 803         if (i && value[i - 1] == ' ')
 804                 quote = "\"";
 805
 806         strbuf_addf(&sb, "\t%.*s = %s",
 807                     length, key + store.baselen + 1, quote);
 808
 809         for (i = 0; value[i]; i++)
 810                 switch (value[i]) {
 811                 case '\n':
 812                         strbuf_addstr(&sb, "\\n");
 813                         break;
 814                 case '\t':
 815                         strbuf_addstr(&sb, "\\t");
 816                         break;
 817                 case '"':
 818                 case '\\':
 819                         strbuf_addch(&sb, '\\');
 820                 default:
 821                         strbuf_addch(&sb, value[i]);
 822                         break;
 823                 }
 824         strbuf_addf(&sb, "%s\n", quote);
 825
 826         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
 827         strbuf_release(&sb);
 828
 829         return success;
 830 }
 831
 832 static ssize_t find_beginning_of_line(const char* contents, size_t size,
 833         size_t offset_, int* found_bracket)
 834 {
 835         size_t equal_offset = size, bracket_offset = size;
 836         ssize_t offset;
 837
 838 contline:
 839         for (offset = offset_-2; offset > 0
 840                         && contents[offset] != '\n'; offset--)
 841                 switch (contents[offset]) {
 842                         case '=': equal_offset = offset; break;
 843                         case ']': bracket_offset = offset; break;
 844                 }
 845         if (offset > 0 && contents[offset-1] == '\\') {
 846                 offset_ = offset;
 847                 goto contline;
 848         }
 849         if (bracket_offset < equal_offset) {
 850                 *found_bracket = 1;
 851                 offset = bracket_offset+1;
 852         } else
 853                 offset++;
 854
 855         return offset;
 856 }
 857
 858 int git_config_set(const char* key, const char* value)
 859 {
 860         return git_config_set_multivar(key, value, NULL, 0);
 861 }
 862
 863 /*
 864  * If value==NULL, unset in (remove from) config,
 865  * if value_regex!=NULL, disregard key/value pairs where value does not match.
 866  * if multi_replace==0, nothing, or only one matching key/value is replaced,
 867  *     else all matching key/values (regardless how many) are removed,
 868  *     before the new pair is written.
 869  *
 870  * Returns 0 on success.
 871  *
 872  * This function does this:
 873  *
 874  * - it locks the config file by creating ".git/config.lock"
 875  *
 876  * - it then parses the config using store_aux() as validator to find
 877  *   the position on the key/value pair to replace. If it is to be unset,
 878  *   it must be found exactly once.
 879  *
 880  * - the config file is mmap()ed and the part before the match (if any) is
 881  *   written to the lock file, then the changed part and the rest.
 882  *
 883  * - the config file is removed and the lock file rename()d to it.
 884  *
 885  */
 886 int git_config_set_multivar(const char* key, const char* value,
 887         const char* value_regex, int multi_replace)
 888 {
 889         int i, dot;
 890         int fd = -1, in_fd;
 891         int ret;
 892         char* config_filename;
 893         struct lock_file *lock = NULL;
 894         const char* last_dot = strrchr(key, '.');
 895
 896         if (config_exclusive_filename)
 897                 config_filename = xstrdup(config_exclusive_filename);
 898         else
 899                 config_filename = git_pathdup("config");
 900
 901         /*
 902          * Since "key" actually contains the section name and the real
 903          * key name separated by a dot, we have to know where the dot is.
 904          */
 905
 906         if (last_dot == NULL) {
 907                 error("key does not contain a section: %s", key);
 908                 ret = 2;
 909                 goto out_free;
 910         }
 911         store.baselen = last_dot - key;
 912
 913         store.multi_replace = multi_replace;
 914
 915         /*
 916          * Validate the key and while at it, lower case it for matching.
 917          */
 918         store.key = xmalloc(strlen(key) + 1);
 919         dot = 0;
 920         for (i = 0; key[i]; i++) {
 921                 unsigned char c = key[i];
 922                 if (c == '.')
 923                         dot = 1;
 924                 /* Leave the extended basename untouched.. */
 925                 if (!dot || i > store.baselen) {
 926                         if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 927                                 error("invalid key: %s", key);
 928                                 free(store.key);
 929                                 ret = 1;
 930                                 goto out_free;
 931                         }
 932                         c = tolower(c);
 933                 } else if (c == '\n') {
 934                         error("invalid key (newline): %s", key);
 935                         free(store.key);
 936                         ret = 1;
 937                         goto out_free;
 938                 }
 939                 store.key[i] = c;
 940         }
 941         store.key[i] = 0;
 942
 943         /*
 944          * The lock serves a purpose in addition to locking: the new
 945          * contents of .git/config will be written into it.
 946          */
 947         lock = xcalloc(sizeof(struct lock_file), 1);
 948         fd = hold_lock_file_for_update(lock, config_filename, 0);
 949         if (fd < 0) {
 950                 error("could not lock config file %s", config_filename);
 951                 free(store.key);
 952                 ret = -1;
 953                 goto out_free;
 954         }
 955
 956         /*
 957          * If .git/config does not exist yet, write a minimal version.
 958          */
 959         in_fd = open(config_filename, O_RDONLY);
 960         if ( in_fd < 0 ) {
 961                 free(store.key);
 962
 963                 if ( ENOENT != errno ) {
 964                         error("opening %s: %s", config_filename,
 965                               strerror(errno));
 966                         ret = 3; /* same as "invalid config file" */
 967                         goto out_free;
 968                 }
 969                 /* if nothing to unset, error out */
 970                 if (value == NULL) {
 971                         ret = 5;
 972                         goto out_free;
 973                 }
 974
 975                 store.key = (char*)key;
 976                 if (!store_write_section(fd, key) ||
 977                     !store_write_pair(fd, key, value))
 978                         goto write_err_out;
 979         } else {
 980                 struct stat st;
 981                 char* contents;
 982                 size_t contents_sz, copy_begin, copy_end;
 983                 int i, new_line = 0;
 984
 985                 if (value_regex == NULL)
 986                         store.value_regex = NULL;
 987                 else {
 988                         if (value_regex[0] == '!') {
 989                                 store.do_not_match = 1;
 990                                 value_regex++;
 991                         } else
 992                                 store.do_not_match = 0;
 993
 994                         store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 995                         if (regcomp(store.value_regex, value_regex,
 996                                         REG_EXTENDED)) {
 997                                 error("invalid pattern: %s", value_regex);
 998                                 free(store.value_regex);
 999                                 ret = 6;
1000                                 goto out_free;
1001                         }
1002                 }
1003
1004                 store.offset[0] = 0;
1005                 store.state = START;
1006                 store.seen = 0;
1007
1008                 /*
1009                  * After this, store.offset will contain the *end* offset
1010                  * of the last match, or remain at 0 if no match was found.
1011                  * As a side effect, we make sure to transform only a valid
1012                  * existing config file.
1013                  */
1014                 if (git_config_from_file(store_aux, config_filename, NULL)) {
1015                         error("invalid config file %s", config_filename);
1016                         free(store.key);
1017                         if (store.value_regex != NULL) {
1018                                 regfree(store.value_regex);
1019                                 free(store.value_regex);
1020                         }
1021                         ret = 3;
1022                         goto out_free;
1023                 }
1024
1025                 free(store.key);
1026                 if (store.value_regex != NULL) {
1027                         regfree(store.value_regex);
1028                         free(store.value_regex);
1029                 }
1030
1031                 /* if nothing to unset, or too many matches, error out */
1032                 if ((store.seen == 0 && value == NULL) ||
1033                                 (store.seen > 1 && multi_replace == 0)) {
1034                         ret = 5;
1035                         goto out_free;
1036                 }
1037
1038                 fstat(in_fd, &st);
1039                 contents_sz = xsize_t(st.st_size);
1040                 contents = xmmap(NULL, contents_sz, PROT_READ,
1041                         MAP_PRIVATE, in_fd, 0);
1042                 close(in_fd);
1043
1044                 if (store.seen == 0)
1045                         store.seen = 1;
1046
1047                 for (i = 0, copy_begin = 0; i < store.seen; i++) {
1048                         if (store.offset[i] == 0) {
1049                                 store.offset[i] = copy_end = contents_sz;
1050                         } else if (store.state != KEY_SEEN) {
1051                                 copy_end = store.offset[i];
1052                         } else
1053                                 copy_end = find_beginning_of_line(
1054                                         contents, contents_sz,
1055                                         store.offset[i]-2, &new_line);
1056
1057                         if (copy_end > 0 && contents[copy_end-1] != '\n')
1058                                 new_line = 1;
1059
1060                         /* write the first part of the config */
1061                         if (copy_end > copy_begin) {
1062                                 if (write_in_full(fd, contents + copy_begin,
1063                                                   copy_end - copy_begin) <
1064                                     copy_end - copy_begin)
1065                                         goto write_err_out;
1066                                 if (new_line &&
1067                                     write_in_full(fd, "\n", 1) != 1)
1068                                         goto write_err_out;
1069                         }
1070                         copy_begin = store.offset[i];
1071                 }
1072
1073                 /* write the pair (value == NULL means unset) */
1074                 if (value != NULL) {
1075                         if (store.state == START) {
1076                                 if (!store_write_section(fd, key))
1077                                         goto write_err_out;
1078                         }
1079                         if (!store_write_pair(fd, key, value))
1080                                 goto write_err_out;
1081                 }
1082
1083                 /* write the rest of the config */
1084                 if (copy_begin < contents_sz)
1085                         if (write_in_full(fd, contents + copy_begin,
1086                                           contents_sz - copy_begin) <
1087                             contents_sz - copy_begin)
1088                                 goto write_err_out;
1089
1090                 munmap(contents, contents_sz);
1091         }
1092
1093         if (commit_lock_file(lock) < 0) {
1094                 error("could not commit config file %s", config_filename);
1095                 ret = 4;
1096                 goto out_free;
1097         }
1098
1099         /*
1100          * lock is committed, so don't try to roll it back below.
1101          * NOTE: Since lockfile.c keeps a linked list of all created
1102          * lock_file structures, it isn't safe to free(lock).  It's
1103          * better to just leave it hanging around.
1104          */
1105         lock = NULL;
1106         ret = 0;
1107
1108 out_free:
1109         if (lock)
1110                 rollback_lock_file(lock);
1111         free(config_filename);
1112         return ret;
1113
1114 write_err_out:
1115         ret = write_error(lock->filename);
1116         goto out_free;
1117
1118 }
1119
1120 static int section_name_match (const char *buf, const char *name)
1121 {
1122         int i = 0, j = 0, dot = 0;
1123         for (; buf[i] && buf[i] != ']'; i++) {
1124                 if (!dot && isspace(buf[i])) {
1125                         dot = 1;
1126                         if (name[j++] != '.')
1127                                 break;
1128                         for (i++; isspace(buf[i]); i++)
1129                                 ; /* do nothing */
1130                         if (buf[i] != '"')
1131                                 break;
1132                         continue;
1133                 }
1134                 if (buf[i] == '\\' && dot)
1135                         i++;
1136                 else if (buf[i] == '"' && dot) {
1137                         for (i++; isspace(buf[i]); i++)
1138                                 ; /* do_nothing */
1139                         break;
1140                 }
1141                 if (buf[i] != name[j++])
1142                         break;
1143         }
1144         return (buf[i] == ']' && name[j] == 0);
1145 }
1146
1147 /* if new_name == NULL, the section is removed instead */
1148 int git_config_rename_section(const char *old_name, const char *new_name)
1149 {
1150         int ret = 0, remove = 0;
1151         char *config_filename;
1152         struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1153         int out_fd;
1154         char buf[1024];
1155
1156         if (config_exclusive_filename)
1157                 config_filename = xstrdup(config_exclusive_filename);
1158         else
1159                 config_filename = git_pathdup("config");
1160         out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1161         if (out_fd < 0) {
1162                 ret = error("could not lock config file %s", config_filename);
1163                 goto out;
1164         }
1165
1166         if (!(config_file = fopen(config_filename, "rb"))) {
1167                 /* no config file means nothing to rename, no error */
1168                 goto unlock_and_out;
1169         }
1170
1171         while (fgets(buf, sizeof(buf), config_file)) {
1172                 int i;
1173                 int length;
1174                 for (i = 0; buf[i] && isspace(buf[i]); i++)
1175                         ; /* do nothing */
1176                 if (buf[i] == '[') {
1177                         /* it's a section */
1178                         if (section_name_match (&buf[i+1], old_name)) {
1179                                 ret++;
1180                                 if (new_name == NULL) {
1181                                         remove = 1;
1182                                         continue;
1183                                 }
1184                                 store.baselen = strlen(new_name);
1185                                 if (!store_write_section(out_fd, new_name)) {
1186                                         ret = write_error(lock->filename);
1187                                         goto out;
1188                                 }
1189                                 continue;
1190                         }
1191                         remove = 0;
1192                 }
1193                 if (remove)
1194                         continue;
1195                 length = strlen(buf);
1196                 if (write_in_full(out_fd, buf, length) != length) {
1197                         ret = write_error(lock->filename);
1198                         goto out;
1199                 }
1200         }
1201         fclose(config_file);
1202  unlock_and_out:
1203         if (commit_lock_file(lock) < 0)
1204                 ret = error("could not commit config file %s", config_filename);
1205  out:
1206         free(config_filename);
1207         return ret;
1208 }
1209
1210 /*
1211  * Call this to report error for your variable that should not
1212  * get a boolean value (i.e. "[my] var" means "true").
1213  */
1214 int config_error_nonbool(const char *var)
1215 {
1216         return error("Missing value for '%s'", var);
1217 }